Matilda / Maud de Mortimer, Baroness Mortimer

I can find noreliable source showing a Maud or Matilda de Longespee either married to Hugh or not (Terry Jackson Curator 5 Feb 2012) and none either showing her as a daughter of William "Clito" & Giovanna.

The following from Medlands suggests that it is impossible that Matilda / Maud de Longespey was married to Hugh de Mortimer:

http://fmg.ac/Projects/MedLands/ENGLISH%20NOBILITY%20MEDIEVAL2.htm

Hugh de Mortimer m ([1150]) as her second husband, MATILDA de Rumilly, widow of PHILIP de Belmeis, daughter of WILLIAM FitzRanulf Meschin, of Skipton-in-Craven & his wife Cecily de Rumilly (-after 1189[239]). The Complete Peerage explains the the documents which confirm her parentage and second marriage[240]: including (1) pleadings in a suit concerning land at Kimbolton, Hampshire, and in a suit dated Jan 1282 in the Chester County Court, which both name Roger de Mortimer as son and heir of "Maud la Meschine"[241]; (2) Roger Mortimer´s grant of rents in Bisley given to him by "his brothers Philip and Ranulph de Belmeis"[242]; (3) “Philippus de Belmeis” founding Lilleshall Abbey, Shropshire by undated charter, witnessed by “Philippus filius Philippi de Belmis…domina Matilda filia Willielmi Meschin uxor prædicti Philippi de Belmis…”[243]. A manuscript narrating the foundation of Wigmore Abbey records that she was “Matildem Longespey, filiam Willielmi Longespey, ducis Normanniæ”[244] but this is confused and cannot possibly be correct. The undated charter, under which "Hugo de Mortuo mari" confirmed various donations to Saint-Victor-en-Caux and other past donations including all donations of property in England "antequam duxissem uxorem"[245], indicates that Hugh married only once.

Hugh & his wife had four children